Malaria is a vector-borne infectious disease caused by protozoan parasites and is widespread in tropical and subtropical regions, including parts of the Americas, Asia and Africa. Of the five Plasmodium parasite species that can infect humans (P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi), the most serious forms of the disease are caused by P. falciparum and P. vivax. Approximately 515 million people are stricken with malaria each year, and between one and three million of these people die from the disease. The current armament of approved anti-malarial drugs, such as chloroquine, atovaquone, pyrimethamine, and sulfadoxine, is limited to only a few targets within the human malaria parasite, and growing widespread resistance to current drugs is prompting the development of new antimalarial agents that have new biological targets.